The Middle East is exploring solar and geothermal energy for desalination

With only 1 percent of desalinated water used in the Middle East being derived sustainably, renewable energy options to produce desalinated water are being explored. With a focus on solar, geothermal energy is though receiving increasing interest in this context.

A recent article published by Nature Middle East, discusses how scientists are lookign for new ways to desalinate water usnign energy resources reducing the dependence on dwindling fossil fuels.

As the author describes the Middle East depends largely on fossil fuels to apply desalination technologies that are then used for growing food. Only about 1 percent of desalinated water comes from renewable energy sources.

While renewable energy provides an opportunity to increase the sustainability of using desalinated water, but the intermittency of availabile solar and wind sources are challenging.

“This is a moment of innovation. You can see that in Saudi Arabia, in Oman, in the Emirates and Qatar and in North African countries. New practices and policies are being developed around water,” said Shannon McCarthy, General Secretary of the International Desalination Association.

Solar energy has been a key area being researched in the context of desalination.

But geothermal energy is increasingly seen as a possible “new frontier”.

To date there is no industrial scale geothermal desalination plant, but it is a mature technology that has been used for generating electricity in Italy, Iceland, China, New Zealand and beyond.

“The world is producing about 12,000 MWe of electricity from hydrothermal power only, why not use it in desalination,” says Dornadula Chandrasekharam, geothermist and former chair of the Department of Earth Sciences at the Indian Institute of Technology in Mumbai, India. Now adjunct professor at King Saud University, Chandrasekharam has analysed the opportunities of tapping geothermal systems from Saudi Arabia. The hot springs and radiogenic granites in the west provide huge potential.

“Immediately Saudi Arabia can develop 40 MWe [about 254 million kWh] from just two thermal springs — Jizan and Al Lith,” he says. If you translate that into desalinated water for say, wheat production, assuming 5700 kWh is for one tonne of wheat and 5.6 tonnes are grown per hectare, about 20 hectares can be brought under irrigation. That’s 120 tonnes of wheat.

Combining high temperature (above 150 degrees Celsius) geothermal energy with a big industrial scale technology, such as hybrid MED-MSF would bring the cost of this water to less than 1.5 Euro, Chandrasekharam says.